Hi,
As far as I know most caravan manufactures do not fit press-studs to their caravans, so I have to assume you have bought the caravan second hand. It is most likely a previous owner has used an awning, and the press-studs will be for the awning skirt.
However If you have a good caravan or tent supplier in your area, you may be able to find matching stud caps, and with a bit of cutting and sewing, you could make some covers from covers from a heavy duty ground sheet material.